A lot of Blake's work is preoccupied with notions of original sin, Milton's Paradise Lost and notions of religion. These underlying influences appear lost on this 'analysis' of the poem, by Linda Grimes, which has a problem with the tree as a metaphor. It's worth a read if only to recognise the metaphor that she does not. It is still dealing with the emotions of resentment and anger, but there is also this metaphor lurking in the depths adding another layer to this simple poem. If you want a hint, what fruit did Eve have a bite of...